The present disclosure relates generally to user authentication and, more particularly, to systems and methods for electronically leashing a user (that is, the user's biological presence within a certain proximity) to a mobile device using radio waves, sound waves, captured imagery, and other sensor data available to the mobile device.
Existing techniques for authenticating a user on a mobile or other computing device require the user to reenter a password, passphrase, PIN, gesture, digital certificate, biometric identifier, or other security identifier (henceforth referred to as primary identifier) each time that the user desires to engage with the device after a period of non-use, or other authenticated state exit conditions such as pressing a button or switching to another application. For example, after a timeout period or pressing a button, the lock screen of the mobile device may reactivate, or the user may have to login again using a primary identifier to secure applications, websites, or other services offered through the device. In other instances, a user may have to enter a primary identifier for each feature or website that the user wants to engage with, even though the user has been previously authenticated by a primary identifier for another use. These reauthentication requirements can be frustrating and cumbersome for the user, particularly if the mobile device has remained in the possession of the user.